The Legendre Transform of Convex Lattice Sets

The goal of this paper is to study convex lattice sets by the discrete Legendre transform. The definition of the polar of convex lattice sets in $\mathbb{Z}^n$ is provided. It is worth mentioning that the polar of convex lattice sets have the self-dual property similar to that of convex bodies. Some properties of convex lattice sets are established, for instance, the inclusion relation, the union and intersection on the polar of convex lattice sets. In addition, we discuss the relationship between the cross-polytope and the discrete Mahler product. It states that a convex lattice set is the cross-polytope if and only if its discrete Mahler product is the smallest.